Grinding mill



w. A. wElDLlcH GRINDING MILL Aug. 29, 1939.

Filed April 27, 1937 es 14 2,3m f5 16 l 17 f7 "19 1 15 l? 17 15 f /-A 18 l fini j' `3 15 i 16' 1s l 96' 10 m mmm Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to mills adapted for grinding paints, varnish, lacquer, pigment, ink or similar substances.

The object is to provide simplified and eiecs tive means for grinding a substance, such for example, as a pigment, and a vehicle, such as a suitable oil. The said substance serving as a lubricant between the surface of the roll and the coacting surface of the shoe, between which surfaces the fit is extremely close, whereby the material may be reduced by a single pass through the mill to 'f, condition of extreme iineness.

' The invention comprises a 4single roll, surmounted by a semi-circular shoe, fitting closely the upper half of the periphery of the roll.

The invention also comprises means for resiliently adjusting the iit or distance between roll and shoe.

The invention also comprises improved regulatable means for feeding the material to the mill, and adjustable means for regulating the rate of feed, and also mechanical means for cooperating in introducing the material between the roll and shoe.

The invention also comprises improved details in construction and operation.

Referring to the drawing which illustrates merely by way of example suitable means for effecting the invention:

Fig. 1 is a section on line 1--1 of Fig. 2.

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is a view similar to Fig. 1, showing a modiiication.

Fig. 4 is an elevation, on a reduced scale, showing the assembly.

Similar numerals refer to similar parts thoughout the several views.

Referring to Figs. 1 and 2. The roller III is mounted on a horizontal shaft II running in suitable bearings I2 supported by a base Il. Surmounting the upper half of roller I is the friction shoe Il having end flanges i5 secured to the base I3 by bolts or studs I8 and the nuts I1. Helical springs I8 are mounted on the studs and interposed between the flanges I5 and the nuts i1, so that an adjustable resilient pressure may be exerted upon the friction shoe at four points which resilient pressure is adapted to cooperate with the gravity pressure of the shoe `upon the upper peripheral surface of the roll. 'I'he shoe I 4 is also provided with lateral arcuate flanges i9 overlapping the outer side margins of the roller, near its periphery. The shaft of roller I0 is provided with a suitable drive pulley 2l. Both roller and shoe are made hollow with suitill iii)

(Cl. Sli-22) able inlets and outlets 2i and 22 for a temperature controlling iluid.

A passage of chamber 23 is provided in or through said shoe I4, having a nozzle 24 extending outwardly from said shoe for connection 5 with a material supply pipe 25. The passage 23 extends laterally approximately the width of the shoe and provides a delivery mouth open to the roller I0, and flares upwardly in the direction of rotation of the roller.

Near the diametrically opposite side of the roller I0, from the point or line of delivery thereto of the material, a suitable scraper 26 is provided for scraping the paste-like material carried on the face of the roller, from said face as it leaves the shoe.

In order to secure a very close smooth fit between the peripheral surface of the roller III and the .cooperating face or surface of the shoe Il, the said surfaces are ground together very smooth and to perfect nt, as by rotating the roller in the shoe with a suitable abrasive, such as emery in oil.

In operation-The shoe is adapted to be held in proper position, with respect to the roller, by means of the nuts i1 on studs I6, operating upon the springs I8. There are two such studs on each end of the shoe. The stud receiving holes 21 in flange I 5, which is on the far side of the shoe, that is the end remote from the intake chamber or passage 23, are sufficiently large to permit slight play on the studs.

The adjustment is made to suit the character of material to be treated, and the degree of fineness desired. 35

In such adjustment, the coacting surface of the shoe is usually spaced very slightly from the peripheral surface of the roller, adjacent the end of the shoe which contains the delivery passage 23. There is a gradually increasing closeness of fit between roller and shoe toward the far end of the shoe, which is adjacent the scraper 26.

As the roller revolves while the shoe is held stationary, the friction between roller and shoe causes a very effective and fine grinding of the material which is carried by the roller around the shoe, while, at the same time, the material acts as a lubricant to prevent injurious friction between roller and shoe.

The mere weight of the shoe would normally cause a close'preliminary engagement between shoe and roller, while the chief function of the resilient adjustment` is to oppose the separating movement of shoe from roller due to the introduction of material therebetween.

In case at any time an undue amount of material should be carried between the roller and shoe, or in case the material should be unduly hard or lumpy, 'the springs will yield slightly to prevent damage to the apparatus. while at the same` time the crushing and grinding pressure is materially increased.

The material is delivered into chamber 23 from any suitable source of supply, such as a tank 28, either by gravity or by pressure above atmosphere. The rate of the supply may be regulated by various regulating means, for example the hand valve 29, or the desired rate of supply or pressure may be created by pumping air into a closed supply tank, or by pumping o! the material to chamber 23 by a variable delivery pump,

such as 30. It may also be desirable to stir the4 material in the tank to facilitate an even or uniform delivery. In such case the usual mixing device, such as 3i, may be provided in the tank. The shoe i4 is provided with the flanking ilanges I9, extending a short distance over the sides of roller ill, to prevent material from discharging laterally from between roller and shoe.

'I'he roller is rotated by any suitable prime mover, such as a variable speed motor 32, at any desired speed, for example 440 R. P. M., and of course the rate of supply and the roller speed are relatively adjustable.

The material to be ground passes between the roller i and shoe il for approximately one-half the circumference of the roller, which causes the pigment particles to be rubbed between the two preferably under a tween the roller and the shoe was sum'cient grind for a mixture of T.02 in blown castor oil and Lindol to produce lacquers extremely high in glaze and free from objectionable agglomerates.

It will be noted that the larger the diameter of the roller, the more emcient the grind. For example, a roller 8 inches in diameter, iltted with a.y

shoe one-half the circumference of the roller, would have approximately 12 inches of actual grind. Whereas a roller 20 inches in diameter, would have approximately 30 inches ot. grinding contact.

In 3, I show a modification of the device, adapted especially for the grinding of harsh pigments, in which'an auxiliary or crushing roller is employed.

'I'his crushing roller 33 is mounted in the upper part of chamber or passage 23, of the shoe I4, with its periphery close to or engaging the periphery of roller Il. As this roller is mounted in the shoe I4, it is automatically adjusted, in relation to the periphery .of roller 10, with the adjustment of the shoe. It may obviously be adjusted in other ways. If this roller 33 is rotated to run at the same R. P. M. as roller I0, in view of the diierence in diameters, it will produce a differential shearing action, which will tend to crush the harder agglomerates of the pigment to a uniform size. The desired ratio between the peripheral speeds of the two rollers may be se- `cured by suitable gearing, such as 34 and 35.

The pump I0, shown in Fig. 4, is marked with the letters PVD, indicating variable delivery pump, so described in column 1 lines 16 and 17 of page 2, and the motor 32, in Fig. 4, is marked with the letters MVS, indicating variable speed motor, so described in column 1 line 26 of page 2.

What I claim is:

In a device of the character described for grinding pigments and similar substances in a fluid vehicle, and especially adapted to eliminate objectionable agglomerates, the combination of a roller mounted to rotate on a horizontal axis, a shoe having a face co-acting with the peripheral surface of the roller which is above the horizontal plane of its axis, said shoe having a limited automatic up-and-down movementduring the operation of the device, said roller and shoe being provided with ground-together co-acting surfaces, secured by rotating the roller within the shoe 'with a suitable abradant, a chamber formed within the shoe, a crushing roller mounted therein and partaking of the said up-and-down movement, and means for delivering material between the peripheral surfaces of the two rollers located adjacent its entrance beneath the shoe, and inthe direction of rotation of the two rollers.

WM. A. WEIDLICH. 

